As the climate heated up, the forests receded, and humans ventured out into the savanna.

随着气候变暖，森林退化，人类铤而走险，进入热带。

The open savanna beneath the trees makes it easy to move around and feed.

树下开阔的热带使得它可以轻松走动和觅食。

In other words, evidence suggesting African savanna elephants give each other names.

换句话说，这表明非洲象会给互相起名字。

Until now, thanks to some wild savanna sparrows.

多亏了某些野生稀树鹀，现我们能用野鸟做实验了。

So, they have to be careful when cruising the African savanna.

因此，它们非洲巡游时必须小心。

A hundred thousand years ago, we were all in the African savanna.

十万年前我们都非洲。

In fact, it transforms from desert to lush savanna about every 21,000 years.

事实上，那里概每隔21000年就会从沙漠变成苍翠的稀树。

It sort of resembled a savanna but without grass.

这就像是一个没有的。

Take the savanna, for example — a transitional biome between forests and grasslands.

以稀树为例，它是森林和之间的过渡生物群落。

They walk twice as far as lions living on the savannas of East Africa.

它们行经的路程是生活东非上的狮子的两倍。

But the thorny acacia are more numerous on the open savanna, where they need to defend themselves.

而有刺的金合欢树更多长开阔的热带中，那，它们需要保护自己。

For instance, all of the plants and animals on the savanna make up the savanna community.

例如，热带系统的所有动植物构成了热带的一个群落。

It's 17,000 feet high, which makes its summit some 30 degrees colder than the surrounding savanna.

海拔超过五千米峰顶，温度比周围的热带低三十度左右。

One key reason is that our ancestors on the savannas of Africa were really good at one thing.

一个关键的因于我们非洲上的祖先真的非常擅长一件事情。

To get away from some lion that wanted us for Sunday brunch on the savannas of East Africa.

远离一些想东非把我们当做周日早午餐吃掉的狮子。

Scientists can easily count the number of savanna elephants from an airplane because there are very few trees.

科学们可以很容易借助飞机数出稀树的象的数量，因为那里的树木非常少。

America during the last Ice Age, it was probably a savanna, with its own set of native earthworms.

当可能就是莽，还有生种的蚯蚓。

Then, all of the savanna's carnivores eat animals that have gotten energy from plants somewhere along the line.

然后，热带上所有的食肉动物都以从植物中获取能量的动物为食。

We need to cross this area of water to get to the savanna and find our locust swarms.

我们要穿过这片区域，才能到达热带找到我们的蝗群。

The fires burned in parts of both the large Cerrado savanna and the world's largest tropical wetland, the Pantanal.

火烧毁了塞拉多和世界上最的热带湿潘塔纳尔的部分区。